CMP pad construction with composite material properties using additive manufacturing processes

ABSTRACT

Embodiments of the disclosure generally provide polishing pads includes a composite pad body and methods for forming the polishing pads. One embodiment provides a polishing pad including a composite pad body. The composite pad body includes one or more first features formed from a first material or a first composition of materials, and one or more second features formed from a second material or a second composition of materials, wherein the one or more first features and the one or more second features are formed by depositing a plurality of layers comprising the first material or first composition of materials and second material or second composition of materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/065,193, filed on Oct. 17, 2014 and U.S. Provisional PatentApplication Ser. No. 62/065,270, filed on Oct. 17, 2014. Each of theaforementioned patent applications is incorporated by reference.

BACKGROUND

Field

Embodiments disclosed herein generally relate to the manufacture ofpolishing articles used in chemical mechanical polishing (CMP)processes. More specifically, embodiments disclosed herein are relatedto composite polishing pads.

Description of the Related Art

Chemical-mechanical polishing (CMP) is commonly used for planarizesubstrates during fabrication of semiconductor devices. During CMP, asubstrate being processed is mounted on a carrier head with the devicesurface placed against a rotating polishing pad. The carrier headprovides a controllable load on the substrate to push the device surfaceagainst the polishing pad. A polishing liquid, such as slurry withabrasive particles, is typically supplied to the surface of thepolishing pad. Polishing pads are consumables for typically become wornafter polishing certain amount of substrates and need to be replaced.

Polishing pads are typically made by molding, casting or sinteringpolyurethane materials. In the case of molding, the polishing pads canbe made one at a time, e.g., by injection molding. In the case ofcasting, the liquid precursor is cast and cured into a cake, which issubsequently sliced into individual pad pieces. These pad pieces canthen be machined to a final thickness. Grooves can be machined into thepolishing surface, or be formed as part of the injection moldingprocess. These methods of manufacturing polishing pads are expensive andtime consuming. Polishing pads manufactured by these methods often yieldnon-uniform polishing results. For example, during CMP, different areason the substrate may be polished at different rates resulting in toomuch material removed (“overpolishing”) in some areas or too littlematerial removed (“underpolishing”) in other areas.

Therefore, there is a need for a polishing pad that provides an improvedpolishing uniformity, and also methods for making the improved polishingpad.

SUMMARY

Embodiments of the disclosure generally provide polishing pads thatinclude a composite pad body and methods for forming the polishing pads.

One embodiment provides a polishing pad including a composite pad body.The composite pad body includes one or more first features formed from afirst material or first composition of materials, and one or more secondfeatures formed from a second material or second composition ofmaterials, wherein the one or more first features and the one or moresecond features are formed by depositing a plurality of layerscomprising the first material or first composition of materials andsecond material or second composition of materials.

Another embodiment provides a method for forming a polishing pad. Themethods include depositing a plurality of composite layers with a 3Dprinter until reaching a target thickness. Depositing each of theplurality of composite layers comprises depositing a first material orfirst composition of materials on one or more first regions, anddepositing a second material or second composition of materials on oneor more second regions, wherein the one or more first regions and theone or more second regions form a continuous area. The method furtherincludes solidifying the composite layers to form a composite pad bodyhaving one or more first features of the first material or firstcomposition of materials and one or more second features of the secondmaterial or second composition of materials, wherein the one or morefirst features and the one or more second features form a unitary body.

Another embodiment provides a polishing pad having a composite pad body.The composite pad body includes a plurality of polishing featuresforming a polishing surface, wherein the plurality of polishing featuresare formed from a first material, and one or more base features formedfrom a second material, wherein the one or more base features jointlysurround the plurality of polishing features to form a unitary body.

One embodiment provides a polishing pad comprising a composite polishingpad body. The composite polishing body comprises one or more firstfeatures formed from a first material, and one or more second featuresformed from a second material. The one or more first features and theone or more second features are formed by depositing a plurality oflayers comprising the first material and the second material.

In one embodiment, the first comprises a first composition of materialsthat is formed by depositing droplets of a third material and a fourthmaterial. In one embodiment, the second material comprises a secondcomposition of materials that is formed by depositing droplets of afifth material and a sixth material.

Yet another embodiment provides a method of forming a polishing pad. Themethod includes depositing a plurality of composite layers with a 3Dprinter to reach a target thickness. Depositing the plurality ofcomposite layers comprises depositing a first material over one or morefirst regions of a surface, and depositing a second material over one ormore second regions of the surface, wherein the one or more firstregions and the one or more second regions form a continuous part ofeach of the plurality of composite layers. The method further includessolidifying the plurality of composite layers to form a composite padbody having one or more first features comprising the first material andone or more second features comprising the second material. The one ormore first features and the one or more second features form a unitarybody.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a schematic sectional view of a polishing station.

FIG. 2A is a schematic perspective sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 2B is a schematic partial top view of a polishing pad according toan embodiment of the present disclosure.

FIG. 2C is a schematic partial sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 2D is a schematic partial sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 3A is a schematic perspective sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 3B is a schematic partial top view of a polishing pad according toan embodiment of the present disclosure.

FIG. 3C is a schematic partial sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 4 is a schematic perspective sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 5 is a schematic perspective sectional view of a polishing padhaving one or more observation windows, according to an embodiment ofthe present disclosure.

FIG. 6 is a schematic perspective sectional view of a polishing padincluding a supporting foam layer, according to an embodiment of thepresent disclosure.

FIG. 7 is a schematic sectional view of a polishing pad having multiplezones, according to an embodiment of the present disclosure.

FIG. 8 is a partial enlarged sectional view of the polishing pad of FIG.7, according to an embodiment of the present disclosure.

FIG. 9 is a schematic perspective sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 10 is a schematic perspective sectional view of a polishing padaccording to an embodiment of the present disclosure.

FIG. 11 is a partial sectional view of the polishing pad of FIG. 10.

FIG. 12 is a schematic sectional view of an apparatus for manufacturingpolishing pads according to an embodiment of the present disclosure.

FIG. 13 is a schematic partial sectional view of a polishing pad havingfeatures formed from a composition of two materials according to anembodiment of the present disclosure.

FIGS. 14A-14O are schematic views of polishing pad designs according toat least one embodiment of the present disclosure.

FIGS. 15A and 15B are schematic views of a polishing pad havingcomposite features, according to at least one embodiment of the presentdisclosure.

FIGS. 16A and 16B are schematic views of a polishing pad havingcomposite features, according to at least one embodiment of the presentdisclosure.

FIGS. 17A and 17B are schematic views of a polishing pad havingcomposite features, according to at least one embodiment of the presentdisclosure.

FIGS. 18A and 18B are schematic views of a polishing pad havingcomposite features, according to at least one embodiment of the presentdisclosure.

FIG. 19 is a schematic sectional view of a polishing station accordingto an embodiment of the present disclosure.

FIG. 20A is a schematic perspective view of a polishing padmanufacturing system according to an embodiment of the presentdisclosure.

FIG. 20B is a schematic view of a polishing pad manufacturing systemaccording to another embodiment of the present disclosure.

FIG. 21A is a schematic view of a 3D printing station according to anembodiment of the present disclosure.

FIG. 21B is a schematic view of a 3D printing station according toanother embodiment of the present disclosure.

FIG. 22 is a schematic perspective view of a polishing pad according toan embodiment of the present disclosure.

To facilitate understanding, common words have been used, wherepossible, to designate identical elements that are common to thefigures. It is contemplated that elements disclosed in one embodimentmay be beneficially utilized on other embodiments without specificrecitation.

DETAILED DESCRIPTION

The present disclosure relates to polishing articles and methods ofmanufacture thereof, as well as methods of polishing substrates andconditioning of the polishing articles before, during and afterpolishing of substrates.

Embodiments of the present disclosure provide a polishing pad having acomposite pad body. The composite pad body includes discrete featuresformed from at least two different materials. The polishing pad may beproduced by a three-dimensional (3D) printing process according toembodiments of the present disclosure. For example, the composite padbody may be formed by successively depositing a plurality of layers,each layer comprising of regions of different materials or differentcompositions of materials, by a 3D printer. In some embodiments, theplurality of layers may then be solidified by curing. The discretefeatures in the composite pad body may be formed simultaneously fromdifferent materials or different compositions of materials. Thedepositing and curing process of 3D printing allow the discrete featuresto be securely joined together. The geometry of the discrete featuresmay be easily controlled using the 3D printing process. By choosingdifferent materials or different compositions of materials, the discretefeatures may have different mechanical, physical, chemical, and/orgeometry properties to obtain target pad properties. In one embodiment,the composite body may be formed from viscoelastic materials havingdifferent mechanical properties. For example the composite body may beformed from viscoelastic materials having different storage moduli anddifferent loss moduli. As a result, the composite pad body may includesome elastic features formed from a first material or a firstcomposition of materials and some hard features formed from a secondmaterial or a second composition of materials that are stiffer than thefirst material or the first composition of materials.

FIG. 1 is a schematic sectional view of a polishing station 100. Thepolishing station 100 may be used in a polishing system to performsubstrate polishing. The polishing station 100 includes a platen 102.The platen 102 may rotate about a central axis 104. A polishing pad 106may be placed on the platen 102. The polishing pad 106 may include acomposite polishing body according to embodiments of the presentdisclosure. The polishing pad 106 includes a polishing surface 112configured to contact and process substrates. The platen 102 supportsthe polishing pad 106 and rotates the polishing pad 106 duringpolishing. A carrier head 108 may hold a substrate 110 being processedagainst the polishing surface 112 of the polishing pad 106. The carrierhead 108 may rotate about a central axis 114 and/or move in a sweepingmotion to generate relative motions between the substrate 110 and thepolishing pad 106. During polishing, a polishing fluid 116, such as anabrasive slurry, may be supplied to the polishing surface 112 by adelivery arm 118. The polishing liquid 116 may contain abrasiveparticles, a pH adjuster and/or chemically active components to enablechemical mechanical polishing of the substrate.

Polishing Pads

FIG. 2A is a schematic perspective sectional view of a polishing pad 200according to one embodiment of the present disclosure. The polishing pad200 may be used in polishing stations, such as the polishing station100, for polishing substrates by chemical mechanical polishing.

The polishing pad 200 includes a composite pad body 202. The compositepad body 202 includes one or more hard features 204 and one or moreelastic features 206. The hard features 204 and the elastic features 206are discrete features that are joined together at boundaries to form thecomposite pad body 202. In one embodiment, the hard features 204 mayhave a hardness of about 40 Shore D scale to about 90 Shore D scale. Theelastic features 206 may have a hardness value between about 26 Shore Ascale to about 95 Shore A scale.

The composite pad body 202 may be formed by 3D printing or othersuitable techniques. The composite pad body 202 may include a pluralityof layers, which each include regions of the elastic features 206 and/orregions of hard features 204 according to the design of the compositepad body 202, that are deposited by a 3D printer. The plurality oflayers may then be cured, for example by UV light or by a heat source,to solidify and achieve a target hardness. After deposition and curing,a unitary composite pad body 202 is formed including the hard features204 and the elastic features 206 that are coupled or joined together.

Materials having different mechanical properties may be selected for theelastic features 206 and the hard features 204 to achieve a targetpolishing process. The dynamic mechanical properties of the elasticfeatures 206 and the hard features 204 may be achieved by selectingdifferent materials and/or choosing different curing processes usedduring the feature forming process. In one embodiment, the elasticfeatures 206 may have a lower hardness value and a lower value ofYoung's modulus, while the hard features 204 may have a higher hardnessvalue and a higher value of Young's modulus. In another embodiment, thedynamic mechanical properties, such as storage modulus and loss modulus,may be adjusted or controlled within each feature and/or by the physicallayout, pattern or combination of elastic features 206 and hard features204 within or across the polishing surface of the polishing pad.

The hard features 204 may be formed from one or more polymer materials.The hard features 204 may be formed from a single polymer material or amixture of two or more polymers to achieve target properties. In oneembodiment, the hard features 204 may be formed from one or morethermoplastic polymers. The hard features 204 may be formed fromthermoplastic polymers, such as polyurethane, polypropylene,polystyrene, polyacrylonitrile, polymethyle methacrylate,polychlorotrifluoroethylene, polytetrafluoroethylene, polyoxymethylene,polycarbonate, polyimide, polyetheretherketone, polyphenylene sulfide,polyether sulfone, acrylonitrile butadiene styrene (ABS),polyetherimide, polyamides, melamines, polyesters, polysulfones,polyvinyl acetates, fluorinated hydrocarbons, and the like, andacrylates, copolymers, grafts, and mixtures thereof. In one embodiment,the hard features 204 may be formed from acrylates. For example, thehard features 204 may be polyurethane acrylate, polyether acrylate, orpolyester acrylate. In another embodiment, the hard features 204 mayinclude one or more thermosetting polymers, such as epoxies, phenolics,amines, polyesters, urethanes, silicon, and acrylates, mixtures,copolymers, and grafts thereof.

In one embodiment, the hard feature may be formed from a simulatingplastic 3D printing material. In one embodiment, abrasive particles maybe embedded in the hard features 204 to enhance the polishing process.The material comprising the abrasive particles may be a metal oxide,such as ceria, alumina, silica, or a combination thereof, a polymer, aninter-metallic or ceramic.

The elastic features 206 may be formed from one or more polymermaterials. The elastic features 206 may be formed from a single polymermaterial or a mixture of two more polymers to achieve target properties.In one embodiment, the elastic features 206 may be formed one or more ofthermoplastic polymers. For example, the elastic features 206 may beformed from thermoplastic polymers, such as polyurethane, polypropylene,polystyrene, polyacrylonitrile, polymethyle methacrylate,polychlorotrifluoroethylene, polytetrafluoroethylene, polyoxymethylene,polycarbonate, polyimide, polyetheretherketone, polyphenylene sulfide,polyether sulfone, acrylonitrile butadiene styrene (ABS),polyetherimide, polyamides, melamines, polyesters, polysulfones,polyvinyl acetates, fluorinated hydrocarbons, and the like, andacrylates, copolymers, grafts, and mixtures thereof. In one embodiment,the elastic features 206 may be formed from acrylates. For example, theelastic features 206 may be polyurethane acrylate, polyether acrylate,or polyester acrylate. In another embodiment, the elastic features 206may be formed from thermoplastic elastomers. In one embodiment, theelastic features 206 may be formed from a rubber-like 3D printingmaterial.

The hard features 204 are generally harder and more rigid than theelastic features 206, while the elastic features 206 are softer and moreflexible than the hard features 204. Materials and patterns of the hardfeatures 204 and the elastic features 206 may be selected to achieve a“tuned” bulk material of the polishing pad 200. The polishing pad 200formed with this “tuned” bulk material has various advantages, such asimproved polishing results, reduced cost of manufacturing, elongated padlife. In one embodiment, the “tuned” bulk material or the polishing padas a whole may have hardness between about 65 shore A to about 75 shoreD. Tensile strength of the polishing pad may be between 5 MPa to about75 MPa. The polishing pad may have about 5% to about 350% elongation tobreak. The polishing pad may have shear strength above about 10 m Pa.The polishing pad may have storage modulus between about 5 MPa to about2000 MPa. The polishing pad may have stable storage modules overtemperature range 25° C. to 90° C. such that storage modulus ratio atE30/E90 falls within the range between about 6 to about 30, wherein E30is the storage modulus at 30° C. and E90 is the storage modulus at 90°C.

In one embodiment, the materials of the hard features 204 and elasticfeatures 206 are chemically resistant to attack from the polishingslurry. In another embodiment, the materials of the hard features 204and elastic features 206 are hydrophilic.

In one embodiment, the hard features 204 and the elastic features 206may be alternating concentric rings alternately arranged to form acircular composite pad body 202. In one embodiment, a height 210 of thehard features 204 is higher than a height 212 of the elastic features206 so that upper surfaces 208 of the hard features 204 protrude fromthe elastic features 206. Grooves 218 or channels are formed between thehard features 204 and the elastic features 206. During polishing, theupper surfaces 208 of the hard features 204 form a polishing surfacethat contacts the substrate, while the grooves 218 retains the polishingfluid. In one embodiment, the hard features 204 are thicker than theelastic features 206 in a direction normal to a plane parallel to thecomposite pad body 202 so that the grooves 218 and/or channels areformed on the top surface of the composite pad body 202.

In one embodiment, a width 214 of the hard features 204 may be betweenabout 250 microns to about 2 millimeters. The pitch 216 between the hardfeatures 204 may be between about 0.5 millimeters to about 5millimeters. Each hard feature 204 may have a width within a rangebetween about 250 microns to about 2 millimeters. The width 214 and/orthe pitch 216 may vary across a radius of the polishing pad 200 to zonesof varied hardness.

Compared with traditional polishing pads, the composite polishing pad200 of the present disclosure has several advantages. Traditionalpolishing pads generally include a polishing layer with a texturedpolishing surface and/or an abrasive materials supported by a subpadformed from a soft material, such as a foam, to obtain target hardnessor Young's modulus for polishing substrates. By selecting materialshaving various mechanical properties, such as Young's modulus, storagemodulus and loss modulus, and adjusting the dimensions and spacing ofthe features or varying arrangement of the different features, desirablehardness, dynamic properties and/or mechanical properties may beachieved in the composite pad body 202 without using a subpad.Therefore, the polishing pad 200 reduces cost of ownership byeliminating subpads. Additionally, hardness and abrasiveness of thepolishing pad 200 may be tuned by mixing features with differenthardness and abrasiveness, therefore, improving polishing performance.

Composite polishing pads according to the present disclosure may havevariable mechanical properties, such as Young's modulus or storagemodulus and loss modulus, across surface features, such as the hardfeatures 204, and base material, such as the elastic features 206, bypattern variation and/or feature size variation. Mechanical propertiesacross the polishing pads may be symmetric or non-symmetric, uniform ornon-uniform to achieve target properties. Pattern of the surfacefeatures may be radial, concentric, rectangular, or random according toachieve target property, such as a predetermined mechanical properties,such as Young's modulus or storage modulus and loss modulus, across thepolishing pad.

In one embodiment, the hard features and the elastic features may beinterlocked to improve the strength of the composite polishing pad andimprove physical integrity of the composite polishing pads. Interlockingof the hard features and elastic features may increase sheer strengthand/or tensile strength of the polishing pad.

FIG. 2B is a schematic partial top view of a polishing pad 200 baccording to one embodiment of the present disclosure. The polishing pad200 b is similar to the polishing pad 200 of FIG. 2A except that thepolishing pad 200 b includes interlocking hard features 204 b andelastic features 206 b. The hard features 204 b and the elastic features206 b may form a plurality of concentric rings. In one embodiment, thehard features 204 b may include protruding vertical ridges 220 and theelastic features 206 b may include vertical recesses 222 for receivingthe vertical ridges 220. Alternatively, the elastic features 206 b mayinclude protruding ridges while the hard features 204 b includerecesses. By having the elastic features 206 b interlock with the hardfeatures 204 b, the polishing pad 200 b will be mechanically stronger inrelation to applied shear forces, which may be generated during the CMPprocess and/or material handling.

FIG. 2C is a schematic partial sectional view of a polishing pad 200 caccording to one embodiment of the present disclosure. The polishing pad200 c is similar to the polishing pad 200 of FIG. 2A except that thepolishing pad 200 c includes interlocking hard features 204 c andelastic features 206 c. The hard features 204 c and the elastic features206 c may include a plurality of concentric rings. In one embodiment,the hard features 204 c may include protruding sidewalls 224 while theelastic features 206 c may include recessing sidewalls 225 to receivethe hard features 204 c. Alternatively, the elastic features 206 c mayinclude protruding sidewalls while the hard features 204 c includerecessing sidewalls. By having the elastic features 206 c interlock withthe hard features 204 c by protruding sidewalls, the polishing pad 200 cobtains an increased tensile strength. Additional, the interlockingsidewalls prevents the polishing pad 200 c from being pulled apart.

FIG. 2D is a schematic partial sectional view of a polishing padaccording to one embodiment of the present disclosure. The polishing pad200 d is similar to the polishing pad 200 c of FIG. 2C except that thepolishing pad 200 d includes differently configured interlockingfeatures. The polishing pad 200 d may include hard features 204 d andelastic features 206 d. The hard features 204 d and the elastic features206 d may include a plurality of concentric rings. In one embodiment,the hard features 204 d may include horizontal ridges 226 while theelastic features 206 d may include horizontal recesses 227 to receivethe horizontal ridges 226 of the hard features 204 d. Alternatively, theelastic features 206 d may include horizontal ridges while the hardfeatures 204 d include horizontal recesses. In one embodiment, verticalinterlocking features, such as the interlocking features of FIG. 2B andhorizontal interlocking features, such as the interlocking features ofFIGS. 2C and 2D, may be combined to form a polishing pad.

FIG. 3A is a schematic perspective sectional view of a polishing pad 300according to one embodiment of the present disclosure. The polishing pad300 includes a plurality of surface features 302 extending from a basematerial layer 304. Upper surfaces 306 of the surface features 302 forma polishing surface for contacting with the substrate during polishing.The surface features 302 and the base material layer 304 have differentproperties. For example, the surface features 302 may be formed from ahard material, such as materials for the hard feature 204 of thepolishing pad 200, while the base material layers 304 may be formed froman elastic material, such as materials for the elastic features 206 ofthe polishing pad 200. The polishing pad 300 may be formed by 3Dprinting, similar to the polishing pad 200.

In one embodiment, the surface features 302 may have substantially thesame size. Alternatively, the surface features 302 may vary in size tocreate varied mechanical property, such as varied Young's modulus orvaried storage modulus and varied loss modulus, across the polishing pad300.

In one embodiment, the surface features 302 may be uniformly distributedacross the polishing pad 300. Alternatively, the surface features 302may be arranged in a non-uniform pattern to achieve target properties inthe polishing pad 300.

In FIG. 3A, the surface features 302 are shown to be circular columnsprotruding from the base material layer 304. Alternatively, the surfacefeatures 302 may be of any suitable shape, for example columns withoval, square, rectangle, triangle, polygonal, or irregular sectionals.In one embodiment, the surface features 302 may be of different shapesto tune hardness of the polishing pad 300.

FIG. 3B is a schematic partial top view of a polishing pad 300 baccording to one embodiment of the present disclosure. The polishing pad300 b is similar to the polishing pad 300 of FIG. 3A except that thepolishing pad 300 b includes a plurality of surface features 302 binterlock with base material layer 304 b. In one embodiment, each of theplurality of surface features 302 b may include protruding verticalridges 310 and the base material layer 304 b may include verticalrecesses 312 for receiving the vertical ridges 310. Alternatively, thebase material layer 304 b may include protruding ridges while thesurface features 302 b include recesses. By having the surface features302 b interlock with the base material layer 304 b, the polishing pad300 b becomes mechanically stronger under an applied shear force.

FIG. 3C is a schematic partial sectional view of a polishing pad 300 caccording to one embodiment of the present disclosure. The polishing pad300 c is similar to the polishing pad 300 of FIG. 3A except that thepolishing pad 300 c includes a plurality of surface features 302 c thatinterlock with base material layer 304 c. In one embodiment, each of theplurality of surface features 302 c may include protruding horizontalridges 314 and the base material layer 304 c may include horizontalrecesses 316 for receiving the horizontal ridges 314. Alternatively, thebase material layer 304 c may include protruding ridges while thesurface features 302 c include recesses. By having the base materiallayer 304 c interlock with the surface features 302 c by use of theprotruding sidewalls, the polishing pad 300 c obtains increased tensilestrength. Additional, the interlocking sidewalls prevents the polishingpad 300 c from being pulled apart during CMP processing or duringhandling of the CMP pad.

In another embodiment, vertical interlocking features, such as theinterlocking features of FIG. 3B and horizontal interlocking features,such as the interlocking features of FIG. 3C, may be combined to form apolishing pad.

FIG. 4 is a schematic perspective sectional view of a polishing pad 400according to one embodiment of the present disclosure. The polishing pad400 includes a base layer 402 that is soft and elastic similar to theelastic features 206 of the polishing pad 200. Similar to the elasticfeatures 206, the base layer 402 may be formed from one or moreelastomeric polymers. The polishing pad 400 includes a plurality ofsurface features 406 extending from the base layer 402. Outer surfaces408 of the surface features 406 may be formed from a soft material or acomposition of soft materials. In one embodiment, the outer surface 408of the surface features 406 may be formed from the same material or thesame composition of materials as the base layer 402. The surfacefeatures 406 may also include a hard feature 404 embedded therein. Thehard features 404 may be formed from a material or a composition ofmaterials that is harder than the surface features 406. The hardfeatures 404 may be formed from materials similar to the material ormaterials of the hard features 204 of the polishing pad 200. Theembedded hard features 404 alter the effective hardness of the surfacefeatures 406, and thus provide a desired target pad hardness forpolishing. The soft polymeric layer of the outer surface 408 can be usedto reduce defects and improve planarization on the substrate beingpolished. Alternatively, a soft polymer material may be printed onsurfaces of other polishing pads of the present disclosure to providethe same benefit.

FIG. 5 is a schematic perspective sectional view of a polishing pad 500having one or more observation windows 510. The polishing pad 500 mayhave a pad body 502. The pad body 502 may include one or more elasticfeatures 506 and a plurality of hard features 504 extending from theelastic features 506 for polishing. The elastic features 506 and thehard features 504 may be formed from materials similar to those for theelastic features 206 and hard features 204 of the polishing pad 200. Thehard features 504 may be arranged in any suitable patterns according tothe present disclosure.

The one or more observation windows 510 may be formed from a transparentmaterial to allow observation of the substrate being polished. Theobservation windows 510 may be formed through, and/or abut portions of,the elastic feature 506 or the hard features 504. In some embodiments,the observation window 510 may be formed from a material that issubstantially transparent, and thus is able to transmit light emittedfrom a laser and/or white light source for use in a CMP optical endpointdetection system. In one embodiment, the observation window 510 may beformed from a transparent 3D printing photopolymer. In one example, theobservation window 510 may be formed from polymethylmethacrylate (PMMA).In some embodiments, the observation window 510 is formed from amaterial that has a low refractive index that is about the same as thatof the polishing slurry and has a high optical clarity to reducereflections from the air/window/water interface and improve transmissionof the light through the observation window 510 to and from thesubstrate. The optical clarity should be high enough to provide at leastabout 25% (e.g., at least about 50%, at least about 80%, at least about90%, at least about 95%) light transmission over the wavelength range ofthe light beam used by the end point detection system's opticaldetector. Typical optical end point detection wavelength ranges includethe visible spectrum (e.g., from about 400 nm to about 800 nm), theultraviolet (UV) spectrum (e.g., from about 300 nm to about 400 nm),and/or the infrared spectrum (e.g., from about 800 nm to about 1550 nm).

FIG. 6 is a schematic perspective sectional view of a polishing pad 600including a backing layer 606. The polishing pad 600 includes a basematerial layer 604 and a plurality of surface features 602 protrudingfrom the base material layer 604. The polishing pad 600 may be similarto the polishing pads 200, 300, 400, 500 described above except havingthe backing layer 606 attached to the base material layer 604. Thebacking layer 606 may provide a desired compressibility to the polishingpad 600. The backing layer 606 may also be used to alter the overallmechanical properties of the polishing pad 600 to achieve a desiredhardness and/or have desired dynamic material properties (e.g., storagemodulus and elastic modulus). The backing layer 606 may have a hardnessvalue of less than 80 Shore A scale.

In one embodiment, the backing layer 606 may be formed from an open-cellor a closed-cell foam, such as polyurethane or polysilicone with voids,so that under pressure the cells collapse and the backing layer 606compresses. In another embodiment, the backing layer 606 may be formedfrom natural rubber, ethylene propylene diene monomer (EPDM) rubber,nitrile, or polychloroprene (neoprene).

FIG. 7 is a schematic sectional view of a polishing pad 700 havingmultiple zones. The polishing pad 700 may be designed to have differentproperties in regions contacting a central area of the substrate andregions contacting edge regions of the substrate during polishing. FIG.7 schematically illustrates the carrier head 108 positioning thesubstrate 110 relative to the polishing pad 700. In one embodiment, thepolishing pad 700 may include a composite pad body 702 disposed on abacking layer 704. The composite pad body 702 may be manufactured by 3Dprinting. As shown in FIG. 7, the polishing pad 700 may be divided intoan outer edge zone 706, a central zone 708 and an inner edge zone 710along the radius of the polishing pad. The outer edge zone 706 and theinner edge zone 710 contact the edge region of the substrate 110 duringpolishing while the central zone 708 contacts the central region of thesubstrate during polishing.

The polishing pad 700 has different mechanical properties, such asYoung's Modulus or storage modulus and loss modulus, on the edge zones706, 708 from the central zone 708 to improve edge polishing quality. Inone embodiment, the edge zones 706, 710 may have a lower Young's modulusthan the central zone 708.

FIG. 8 is a partial enlarged sectional view of the polishing pad 700showing exemplary designs for the outer edge zone 706 and the centralzone 708. The outer edge zone 706 includes a base material layer 806 anda plurality of surface features 802. The surface features 804 may beformed from materials harder than the base material layer 806. Thecentral zone 708 includes a base material layer 808 and a plurality ofsurface features 804. The surface features 802 may be formed frommaterials harder than the base material layer 808. In one embodiment,the central zone 708 may include a locking layer 810 under the basematerial layer 808. The locking layer 810 may be formed from a hardmaterial, such as the material for the surface features 302 or hardfeatures 202. The plurality of surface features 804 may be printed onthe locking layer 810 to improve stability. As shown in FIG. 8, thesurface features 802 in the central zone 708 are larger in size than thesurface features 804 in the outer edge zone 706. In one embodiment, thepitch of the surface features 804 in the outer edge zone 706 may besmaller than the pitch of the surface features 802 in the central zone708.

FIG. 9 is a schematic sectional view of a polishing pad 900 having twodifferent polishing surfaces 902, 904. The polishing pad 900 is acomposite polishing pad including discrete features. The polishingsurfaces 902, 904 may have different patterns and/or different hardnessand abrasiveness. In one embodiment, the polishing surface 904 may be ahard and abrasive surface for polishing a substrate and the polishingsurface 904 may be soft buff surface. During polishing, while thepolishing pad 900 rotates about its central axis (e.g., center ofpolishing pad extending out of the page of the drawing), the substrate110 is alternatively exposed to the two polishing surfaces 902, 904during each rotation of the polishing pad. If the polishing surface 902is configured to perform a bulk polishing and the polishing surface 904is configured to perform a buff polishing, the polishing pad 900performs both bulk polishing and buff polishing at each rotation, thusenable two stages of polishing to be performed at the same time.

FIG. 10 is a schematic sectional view of a polishing pad 1000. Thepolishing pad 1000 may include two or more composite pad bodies 1002,1006, 1004. The composite pad bodies 1002, 1004, 1006 may be formed by3D printing. The composite pad bodies 1002, 1004, 1006 may have the sameor different patterns formed thereon. The composite pad bodies 1002,1004, 1006 may include locking features 1008, 1010 to securely connectwith one another to form the polishing pad 1000. The multiple compositepad body configuration provides flexibility to polishing padmanufacturing and/or transportation.

FIG. 11 is a partial sectional view of the composite pad bodies 1002 and1004 showing a locking feature according to one embodiment of thepresent disclosure. For example, the locking feature 1008 may be ahorizontal ridge while the locking feature 1010 may be a horizontalrecess for receiving a horizontal ridge. Any suitable locking featuresmay be used to join the composite pad bodies 1002, 1004, 1006.

3D Printing Stations

FIG. 12 is a schematic sectional view of a 3D printing station 1200 formanufacturing polishing pads according to the present disclosure. Thepolishing pad 200 may be printed on a support 1202. The polishing pad200 is formed by a droplet ejecting printer 1206 from a CAD(computer-aided design) program. The droplet ejecting printer 1206 andthe support 1202 may move relative to each other during the printingprocess.

The droplet ejecting printer 1206 may one or more print heads havingnozzles for dispensing liquid precursors. In the embodiment of FIG. 12,the droplet ejecting printer 1206 include a print head 1208 having anozzle 1210 and a print head 1214 having a nozzle 1212. The nozzle 1210may be configured to dispense a liquid precursor for a first material,such as a soft or elastic material, while the nozzle 1212 may be used todispense a liquid precursor for a second material, such as a hardmaterial. In other embodiment, the droplet ejecting printer 1206 mayinclude more than two print heads to form polishing pads with more thantwo materials. The liquid precursors may be dispensed only at selectedlocations or regions to form the polishing pad 200. These selectedlocations collectively form the target printing pattern of surfacefeatures and base material layer and can be stored as a CAD-compatiblefile that is then read by an electronic controller 1204 (e.g., acomputer) that controls the droplet ejecting printer 1206.

3D printing processes as described herein includes, but is not limitedto, polyjet deposition, inkjet printing, fused deposition modeling,binder jetting, powder bed fusion, selective laser sintering,stereolithography, vat photopolymerization digital light processing,sheet lamination, directed energy deposition, among other 3D depositionor printing processes.

After 3D printing, the polishing pads may be solidified by curing.Curing may be performed by heating the printed polishing pads to acuring temperature. Alternatively, curing may be performed by exposingthe printed polishing pad to an ultraviolet light beam generated by anultra violet light source.

3D printing offers a convenient and highly controllable process forproducing polishing pads with discrete features formed from differentmaterials and/or different compositions of materials. In one embodiment,the elastic features and/or the hard features of a polishing pad may beformed from a single material. For example, the elastic features of apolishing pad may be formed from the first material dispensed from theprint head 1210. The hard features of the polishing pad may be formedfrom droplets of the second material dispensed from the print head 1212.

In another embodiment, the elastic features and/or the hard features maybe formed from a mixture of two or more materials. FIG. 13 is aschematic partial sectional view of a polishing pad 1300 having hardfeatures 1304 a, 1304 b formed from a composition of two materials. Thehard features 1304 a, 1304 b may be formed from a mixture of a firstmaterial and a second material. The first material may be dispensed inthe form of droplets 1316 by a first print head, such as the print head1210, and the second material may be dispensed in the form of droplets1318 by a second print head, such as the print head 1212. To form thehard feature 1304 a with a mixture of the droplets 1316 and the droplets1318, the print head 1212 may first align with pixels corresponding tothe hard feature 1304 a and dispense droplets 1318 on predeterminedpixels. The print head 1210 may then align with the pixels correspondingto the hard feature 1304 a and dispense droplets 1316 on predeterminedpixels. As a result, a layer including droplets 1316 and droplets 1318is added to the hard feature 1304 a. The polishing pad may thus beformed from a first material that comprises a first composition ofmaterials that is formed by depositing droplets of one or more materialsand a second material that comprises a second composition of materialsthat is formed by depositing droplets of one or more differentmaterials.

Properties of the hard feature 1304 a, 1304 b may be adjusted or tunedaccording to the ratio and/or distribution of the first material and thesecond material. In one embodiment, the composition of the hard features1304 a, 1304 b is controlled by selecting size, location, speed, and/ordensity of the droplets 1316, 1318.

The hard features 1304 a, 1304 b may have identical compositions.Alternatively, each hard feature 1304 a, 1304 b may have anindividualized composition. Similarly, elastic features 1306 may beformed from a mixture of materials as well. Compositions of each elasticfeature 1306 may also be individualized to achieve target properties.Even though only two materials are used in forming the features 1304 a,1304 b, embodiments of the present disclosure encompass forming featureson a polishing pad with a plurality of materials. In someconfigurations, the composition of the hard and/or elastic features in apolishing pad are adjusted within a plane parallel to the polishingsurface and/or through the thickness of the polishing pad, as discussedfurther below.

Polishing Pad Patterns

FIGS. 14A-14O are schematic views of polishing pad designs according toembodiments of the present disclosure. Each of the FIGS. 14A-14O includepixel charts having white regions (regions in white pixels) thatrepresent polishing features 1402 a-1402 o for contacting and polishinga substrate, and black regions (regions in black pixels) that representthe base features 1404 a-1404 o. The polishing features 1402 a-1402 omay be similar to the hard features 204 of the polishing pad 200. Thebase features 1404 a-1404 o may be similar to the elastic features 206of the polishing pad 200. The white regions generally protrude over theblack regions so that channels are formed in the black regions betweenthe white regions. Polishing slurry may flow through and may be retainedin the channels during polishing. The polishing pads shown in FIGS.14A-14O may be formed by depositing a plurality of layers of materialsusing a 3D printer. Each of the plurality of layers may include two ormore materials to form the polishing features 1402 a-1404 o and the basefeatures 1404 a-1404 o. In one embodiment, the polishing features 1402a-1402 o may be thicker than the base features 1404 a-1404 o in adirection normal to a plane that is parallel to the plurality of layersof materials so that grooves and/or channels are formed on a top surfaceof the polishing pad.

FIG. 14A is a schematic pixel chart of a polishing pad design 1400 ahaving a plurality of concentric polishing features 1402 a. Thepolishing features 1402 a may be concentric circles of identical width.In one embodiment, the base features 1404 a may also have identicalwidth so that the pitch of the polishing features 1402 a is constantalong the radial direction. During polishing, channels between thepolishing features 1402 a retain the polishing slurry and prevent rapidloss of the polishing slurry due to a centrifugal force generated byrotation of the polishing pad about its central axis (i.e., center ofconcentric circles).

FIG. 14B is a schematic pixel chart of a polishing pad design 1400 bhaving a plurality of segmented polishing features 1402 b arranged inconcentric circles. In one embodiment, the segmented polishing features1402 b may have substantially identical length. The segmented polishingfeatures 1402 b may form a plurality of concentric circles. In eachcircle, the segmented polishing features 1402 b may be equallydistributed within each concentric circle. In one embodiment, thesegmented polishing features 1402 b may have an identical width in theradial direction. In some embodiments, the segmented polishing features1402 b each substantially have an identical length irrespective of theradius is of the concentric circle (e.g., equal arc length except forthe center region of the polishing pad). In one embodiment, the basefeatures 1404 b between the plurality of concentric circles may alsohave identical width so that the pitch of the concentric circles isconstant. In one embodiment, gaps between the segmented polishingfeatures 1402 b may be staggered from circle to circle to preventpolishing slurry from directly flowing out of the polishing pad underthe centrifugal force generated by rotation of the polishing pad aboutits central axis.

FIG. 14C is a schematic pixel chart of a polishing pad design 1400 chaving a plurality of concentric polishing features 1402 c formed overbase features 1404 c. The pad design in FIG. 14C is similar to the paddesign 1400 a in FIG. 14A except the widths of the polishing features1402 c gradually vary along the radial direction. In one embodiment, thewidths of the polishing features reduce from a center of the polishingpad towards an edge of the polishing pad while the distance betweenneighboring polishing features 1402 c remain constant. The variation ofthe width of the polishing features 1402 c may be used to compensate thedifference in linear speed of the substrate being polished at variousradial locations of the polishing pad, while the polishing pad isrotating about a center axis.

FIG. 14D is a schematic pixel chart of a polishing pad design 1400 dhaving a plurality of concentric polishing features 1402 d formed overbase features 1404 d. The pad design in FIG. 14D is similar to the paddesign 1400 a in FIG. 14A except the polishing features 1402 d areelliptical instead of circular. The elliptical polishing features 1402 dwill allow any radial location on the polishing pad to have polishingfeatures of multiple dimensions and orientations, thus, improvingpolishing uniformity.

FIG. 14E is a schematic pixel chart of a polishing pad design 1400 ehaving a plurality of concentric elliptical polishing features 1402 eformed over base features 1404 e. The pad design in FIG. 14E is similarto the pad design 1400 d in FIG. 14D except the elliptical polishingfeatures 1402 e vary in width along a radial direction. The ellipticalpolishing features with varied width will allow a radial location on thepolishing pad to have more variation in the polishing features thatcontact a substrate during polishing, thus, improving polishinguniformity.

FIG. 14F is a schematic pixel chart of a polishing pad design 1400 fhaving spiral polishing features 1402 f over base features 1404 f. InFIG. 14F, the polishing pad 1400 f has four spiral polishing features1402 f extending from a center of the polishing pad to an edge of thepolishing pad. Even though four spiral polishing features are shown,less or more numbers of spiral polishing features 1402 f may be arrangedin similar manner. The spiral polishing features 1402 f define spiralchannels. In one embodiment, each of the spiral polishing features 1402f has a constant width. In one embodiment, the spiral channels also havea constant width. During polishing, the polishing pad may rotate about acentral axis in a direction opposite to the direction of the spiralpolishing features 1402 f to retain polishing slurry in the spiralchannels. For example, in FIG. 14F, the spiral polishing features 1402 fand the spiral channels are formed in a counter-clockwise direction, andthus during polishing the polishing pad may be rotated clockwise toretain polishing slurry in the spiral channels and on the polishing pad.In some configurations, each of the spiral channels is continuous fromthe center of the polishing pad to the edge of the polishing pad. Thiscontinuous spiral channels allow polishing slurry along with anypolishing waste to flow from the center of the polishing pad to the edgeof the polishing pad. In one embodiment, the polishing pad may becleaned by rotating the polishing pad in the same direction as thespiral polishing features 1402 f (e.g., counter-clockwise in FIG. 14F).

FIG. 14G is a schematic pixel chart of a polishing pad design 1400 ghaving segmented polishing features 1402 g arranged in a spiral patternon base features 1404 g. The polishing pad in FIG. 14G is similar to thepolishing pad in FIG. 14F except that the spiral polishing features 1402g are segmented. In one embodiment, the segmented polishing features1402 g are substantially the same length. The segmented polishingfeatures 1402 g may be equally distributed along each spiral polishingfeature. In some embodiments, the segmented polishing features 1402 gmay each substantially have an identical length in the spiral direction.

FIG. 14H is a schematic pixel chart of a polishing pad design 1400 hhaving segmented polishing features 1402 h arranged in a spiral patternon base features 1404 h. The polishing pad in FIG. 14H is similar to thepolishing pad in FIG. 14G except that the segmented polishing features1402 h vary in length. In one embodiment, the lengths of the segmentedpolishing features 1402 h increase from a center of the polishing pad toan edge region of the polishing pad.

FIG. 14I is a schematic pixel chart of a polishing pad design 1400 ihaving segmented polishing features 1402 i arranged in a spiral patternon base features 1404 i. The polishing pad in FIG. 14I is similar to thepolishing pad in FIG. 14G except that radial pitch of the segmentedpolishing features 1402 i varies. In one embodiment, the radial pitch ofthe segmented polishing features 1402 i decreases from a center of thepolishing pad to an edge region of the polishing pad.

FIG. 14J is a schematic pixel chart of a polishing pad design 1400 jhaving segmented polishing features 1402 j arranged in a spiral patternon base features 1404 j. The polishing pad in FIG. 14J is similar to thepolishing pad in FIG. 14I except that radial pitch of the segmentedpolishing features 1402 j increases from a center of the polishing padto an edge region of the polishing pad.

FIG. 14K is a schematic pixel chart of a polishing pad design 1400 khaving a plurality of discrete polishing features 1402 k formed in basefeatures 1404 k. In one embodiment, each of the plurality of polishingfeatures 1402 k may be a cylindrical post. In one embodiment, theplurality of polishing features 1402 k may have the same dimension inthe plane of the polishing surface. In one embodiment, the plurality ofcylindrical polishing features 1402 k may be arranged in concentriccircles. In one embodiment, the plurality of cylindrical polishingfeatures 1402 k may be arranged in a regular 2D pattern relative to theplane of the polishing surface.

FIG. 14L is a schematic pixel chart of a polishing pad design 1400 lhaving a plurality of discrete polishing features 1402 l formed overbase features 1404 l. The polishing pad of FIG. 14L is similar to thepolishing pad of FIG. 14K except that each of the discrete polishingfeatures 1402 l in FIG. 14L may be hollow cylindrical post, or have adepression relative to the polishing surface, formed therein. The hollowcylindrical posts allow some polishing slurry to be retained therein.

FIG. 14M is a schematic pixel chart of a polishing pad design 1400 mhaving a plurality of discrete polishing features 1402 m formed overbase features 1404 m. The polishing pad of FIG. 14M is similar to thepolishing pad of FIG. 14K except that some polishing features 1402 m inFIG. 14M may be connected to form one or more closed circles. The one ormore closed circles may create one or more damns to retain polishingslurry during polishing.

FIG. 14N is a schematic pixel chart of a polishing pad design 1400 nhaving a plurality of discrete polishing features 1402 n formed in basefeatures 1404 n. The polishing pad of FIG. 14N is similar to thepolishing pad of FIG. 14M except that some polishing features 1402 n inFIG. 14N may be connected to form one or more spiral chains. The one ormore spiral chains may guide the fluid flow of the polishing slurry toassist polishing slurry retention and polishing pad cleaning.

FIG. 14O is a schematic pixel chart of a polishing pad design 1400 ohaving a plurality of discrete polishing features 1402 o and basefeatures 1404 o. The polishing pad of FIG. 14O is similar to thepolishing pad of FIG. 14K except that each of the discrete polishingfeatures 1402 o in FIG. 14O is in the shape of the logo of AppliedMaterials, Inc. FIG. 14O demonstrates that embodiments of the presentdisclosure encompass polishing pads having polishing features with anysuitable design, pattern and/or arrangement.

The polishing features 1402 a-1402 o in the designs of FIGS. 14A-14O maybe formed from identical material or identical composition of materials.Alternatively, the material composition and/or material properties ofthe polishing features 1402 a-1402 o in the designs of FIG. 14A-14O mayvary from polishing feature to polishing feature. Individualizedmaterial composition and/or material properties allows polishing pads tobe tailored for specific needs.

When polishing features are formed from two different 3D printingmaterials, the polishing feature may be manufactured by printing atleast two superimposed images using two print heads. FIGS. 15A-15B toFIGS. 18A-18B provide examples of the designs for polishing pads withcomposite polishing features. In FIGS. 15-18, the white pixels marks arewhere a droplet of material is dispensed while the black pixels markwhere no material is dispensed within one or more layers used to form apolishing pad. By use of these techniques, gradients in materialcomposition can be formed in one or more of the printed layers used toform at least part of a complete polishing pad. The tailored compositionof one or more of the printed layers within a polishing pad can be usedto adjust and tailor the overall mechanical properties of the polishingpad.

By use of these techniques, in some embodiments, it is desirable to forma gradient in material composition in a direction normal to thepolishing surface of the polishing pad (e.g., direction normal toillustrations shown in FIGS. 15-18) or in the plane of the polishingsurface of the polishing pad (e.g., radial direction). In oneembodiment, it is desirable to form a gradient in the materialcomposition in the hard and/or elastic features, which are discussedabove, in a direction normal to the polishing surface of the polishingpad. In one example, it is desirable to have higher concentrations of amaterial used to form the elastic features in the printed layers nearthe base of the polishing pad (e.g., opposite to the polishing surface),and higher concentrations of a material used to form the hard featuresin the printed layers near the polishing surface of the polishing pad.In another example, it is desirable to have higher concentrations of amaterial used to form the hard features in the printed layers near thebase of the polishing pad, and a higher concentration of a material usedto form the elastic features in the printed layers near the polishingsurface of the polishing pad.

Gradients in the material composition and/or material properties of thestacked 3D printed layers can vary from a high concentration to a lowconcentration in one direction, or vice versa. In some cases, one ormore regions with polishing pad may include more complex concentrationgradients, such as a high/low/high or low/high/low concentrationgradient. In one configuration, a gradient in concentration can beformed by varying the position and/or amount of a first printedcomponent to a second printed component in each successive layer of aformed polishing pad. For example, a first layer may have a ratio of thefirst printed component to the second printed component of 1:1, a ratioof the first printed component to the second printed component of 2:1 ina second layer and a ratio of the first printed component to the secondprinted component of 3:1 in a third layer. A gradient can also be formedwithin different parts of a single layer by adjusting the placement ofthe printed droplets within the plane of the deposited layer.

FIGS. 15A and 15B are black and white bitmap images reflecting pixelcharts of a polishing pad having composite features. In FIGS. 15A, 15B,the white pixels mark are where a droplet of material is dispensed whilethe black pixels mark where no material is dispensed. FIG. 15A is thepixel chart 1500 a of a first material for a polishing pad and FIG. 15Bis the pixel chart 1500 b of a second material for the same polishingpad. The first material may be dispensed by a first print head accordingto the pixel chart 1500 a and the second material may be dispensed by asecond print head according to the pixel chart 1500 b. The two printheads superimpose the pixel charts 1500 a, 1500 b together to form aplurality of discrete polishing features. The polishing features near anedge region of the polishing pad include more of the first material thanthe second material. The polishing features near a center region of thepolishing pad include more of the second material than the firstmaterial. In this example, each polishing feature has a uniquecomposition of the first material and the second material.

FIGS. 16A and 16B are schematic pixel charts 1600 a, 1600 b of apolishing pad having composite features. FIG. 16A is the pixel chart1600 a of a first material for a polishing pad and FIG. 16B is the pixelchart 1600 b of a second material for the same polishing pad. Thepolishing pad according to FIGS. 16A, 16B is similar to the polishingpad of FIGS. 15A, 15B except that the polishing features are larger inFIGS. 16A, 16B.

FIGS. 17A and 17B are schematic pixel charts 1700 a, 1700 b of apolishing pad having composite features. FIG. 17A is the pixel chart1700 a of a first material for a polishing pad and FIG. 17B is the pixelchart 1700 b of a second material for the same polishing pad. Thepolishing pad according to FIGS. 17A, 17B is similar to the polishingpad of FIGS. 15A, 15B except the composition of the polishing featuresvaries from left to right across the polishing pad.

FIGS. 18A and 18B are schematic pixel charts 1800 a, 1800 b of apolishing pad having composite features. FIG. 18A is the pixel chart1800 a of a first material for a polishing pad and FIG. 18B is the pixelchart 1800 b of a second material for the same polishing pad. Thepolishing pad according to FIGS. 18A, 18B is similar to the polishingpad of FIGS. 17A, 17B except the polishing features are larger in FIGS.18A, 18B.

It should be noted that the composition of polishing features may varyin any suitable pattern. Although polishing pads described above areshown to be formed from two kinds of materials, composite polishing padsincluding three or more kinds of features are within the scope of thepresent disclosure.

It should be noted that compositions of the polishing features in anydesigns of the polishing pad, such as the polishing pads in FIGS.14A-14O, may be varied in similar manner as the polishing pads in FIGS.15-18.

Additive Manufacturing and Curing Techniques

FIG. 19 depicts a sectional view of an exemplary CMP station 1902 havinga carrier head assembly 1900 positioned over a platen assembly 1911. Thecarrier head assembly 1900 generally comprises a drive system 1901coupled to a carrier head 1921. The drive system 1901 may be coupled toa controller (not shown) that provides a signal to the drive system 1901for controlling the rotational speed and direction of the carrier head1921. The drive system 1901 generally provides at least rotationalmotion to the carrier head 1921 and additionally may be actuated towardthe platen assembly 1911 such that a feature 1904 side of the substrate1914, retained in the carrier head 1921, may be disposed against a 1925processing surface of a pad assembly 1913 of the CMP station 1902 duringprocessing. Typically, the substrate 1914 and processing pad assembly1913 are rotated relative to one another to remove material from thefeature side 1904 of the substrate 1914. Depending on processparameters, the carrier head 1921 is rotated at a rotational speedgreater than, less than, or equal to, the rotational speed of the platenassembly 1911. The carrier head assembly 1900 is also capable ofremaining fixed and may move in a path during processing. The carrierhead assembly 1900 may also provide an orbital or a sweeping motionacross the processing surface 1925 of the pad assembly 1913 duringprocessing. The pad assembly 1913 may be adapted to releasably couple toan upper surface of the platen assembly 1911 using an adhesive layer1906. The pad assembly 1913 generally includes the processing surface1925, the adhesive layer 1906, and may include an optional backing layer1907.

The platen assembly 1911 is rotationally disposed on a base 1908 and istypically supported above the base 1908 by a bearing 1938 so that theplaten assembly 1911 may be rotated relative to the base 1908. Theplaten assembly 1911 may be fabricated from a rigid material, such as ametal or rigid plastic, and in one embodiment the platen assembly 1911has an upper surface that is fabricated from or coated with a dielectricmaterial, such as CPVC. The platen assembly 1911 may have a circular,rectangular or other plane form.

A polishing fluid may be provided from a polishing fluid source 1948,through appropriate plumbing and controls to nozzle a 1917 positionedabove the processing pad assembly 1913 of the CMP station 1902. In theembodiment shown in FIG. 19, a polishing fluid 1941 is provided from thenozzle 1917. The polishing fluid 1941 may be contained by a platen lip1958. The polishing fluid 1941 may be deionized water (DIW) or otherpolishing fluid consisting primarily of water (e.g., DIW), or a slurryhaving abrasive particles entrained in DIW.

The processing surface 1925 of the pad assembly 1913 may further includea patterned surface 1951 formed on the upper surface thereof tofacilitate polishing of the substrate 1914. Patterns of the patternedsurface 1951 may include a plurality of small protrusions extendingabove the processing surface 1925. The protrusions may take anygeometrical form, such as ovals, circles, rectangles, hexagons,octagons, triangles, or combinations thereof and may be formed by athree-dimensional printing process as described herein. The patternedsurface 1951 may be maintained and/or refreshed using a conditioningdevice 1955 positioned to interact with the processing surface 1925 ofthe pad assembly 1913. In one embodiment, the conditioning device 1955comprises an electromagnetic energy source 1959. The electromagneticenergy source 1959 is a laser in one embodiment, and is utilized to emitone or more beams 1960 of electromagnetic energy toward the processingsurface 1925. The one or more beams 1960 of electromagnetic energy areutilized to selectively heat and/or ablate multiple regions of theprocessing surface 1925 in order to refresh or maintain the patternedsurface 1951 thereon. In some embodiments, the electromagnetic energysource 1959 may be utilized to tune the processing surface 1925 of thepad assembly 1913 by selectively heating discrete regions of theprocessing surface 1925.

FIG. 20A is a schematic isometric view of one embodiment of a padmanufacturing system 2000A for preparing a pad assembly that may be usedon a platen assembly, for example the pad assembly 1913 used in theplaten assembly 1911 of FIG. 19. In one embodiment, the padmanufacturing system 2000A generally includes a feed section 2002, aprint section 2004 and a curing section 2006. The pad manufacturingsystem 2000A is utilized to produce a plurality of printed pads 2008that may be used as the pad assembly 1913 in the platen assembly 1911 ofFIG. 19. While not shown, the pad manufacturing system 2000A may also bemodified to print a pad for use in a roll-to-roll polishing system.

The pad manufacturing system 2000A also includes a conveyor 2010including a web 2012 disposed between at least two rollers 2014. One orboth of the rollers 2014 may be coupled to a drive motor 2015 thatrotates the rollers 2014 and/or the web 2012 in the direction depictedby the arrow indicated at A. The feed section 2002, the print section2004 and the curing section 2006 may be operably coupled to a controller2011. The conveyor 2010 may be operated to move continuously orintermittently by the controller 2011.

The feed section 2002 may include a supply roll 2016 that is operablycoupled to the conveyor 2010. The supply roll 2016 may be a backingmaterial 2017, such a polymeric material, for example, abiaxially-oriented polyethylene terephthalate (BoPET) material. Thesupply roll 2016 may be disposed on a feed roller 2018 that is driven orcontrolled by a motion control device 2020. The motion control device2020 may be a motor and/or include a brake system that provides apredetermined tension on the supply roll 2016 such that the unwindingspeed of the supply roll 2016 is driven by the drive motor 2015 and/orthe web 2012. The feed section 2002 may also include a pretreatmentdevice 2022. The pretreatment device 2022 may be configured to spray orotherwise provide a coating onto the backing material 2017 prior toprinting at the print section 2004. In some embodiments, thepretreatment device 2022 may be utilized to heat the backing material2017 prior to printing at the print section 2004.

The print section 2004 includes a 3D printing station 2024 disposeddownstream of the feed section 2002. The print section 2004 utilizes oneor more print heads 2027 to provide a patterned surface 2028 onto thebacking material 2017. The print section 2004 may include a movableplatform 2030 that is coupled to a motion control device 2032 that maybe utilized to move the print heads 2027 relative to the backingmaterial 2017 and the web 2012.

The print heads 2027 may be coupled to a material source 2025 havingprint materials that may be used to form the patterned surface 2028.Print materials may include polymeric materials such as polyurethanes,polycarbonates, fluoropolymers, PTFE, PTFA, polyphenylene sulfide (PPS),or combinations thereof. Examples also include polyvinyl alcohols,pectin, polyvinyl pyrrolidone, hydroxyethylcellulose, methylcellulose,hydropropylmethylcellulose, carboxymethylcellulose,hydroxypropylcellulose, polyacrylic acids, polyacrylamides, polyethyleneglycols, polyhydroxyetheracrylites, starches, maleic acid copolymers,polyethylene oxide, polyurethanes and combinations thereof, or any ofthe other materials described above.

In one embodiment, a polymeric material may be deposited as a basematerial on the backing material 2017. The polymeric material formed maycomprise an open-pored or closed-pored polyurethane material, and mayinclude nano-scale particles interspersed therein. The particles mayinclude organic nanoparticles. In one embodiment, the nanoparticles mayinclude molecular or elemental rings and/or nanostructures. Examplesinclude allotropes of carbon (C), such as carbon nanotubes and otherstructures, molecular carbon rings having 5 bonds (pentagonal), 6 bonds(hexagonal), or more than 6 bonds. Other examples include fullerene-likesupramolecules. In another embodiment, the nano-scale particles may be aceramic material, alumina, glass (e.g., silicon dioxide (SiO₂)), andcombinations or derivatives thereof. In another embodiment, thenano-scale particles may include metal oxides, such as titanium (IV)oxide or titanium dioxide (TiO₂), zirconium (IV) oxide or zirconiumdioxide (ZrO₂), combinations thereof and derivatives thereof, amongother oxides.

The patterned surface 2028 formed by the print heads 2027 may comprise acomposite base material, such as a polymeric matrix, which may be formedfrom urethanes, melamines, polyesters, polysulfones, polyvinyl acetates,fluorinated hydrocarbons, and the like, and mixtures, copolymers andgrafts thereof. In one embodiment, the polymeric matrix comprises aurethane polymer that may be formed from a polyether-based liquidurethane. The liquid urethane may be reactive with a polyfunctionalamine, diamine, triamine or polyfunctional hydroxyl compound or mixedfunctionality compounds, such as hydroxyl/amines in urethane/ureacross-linked compositions that form urea links and a cross-linkedpolymer network when cured.

The curing section 2006 includes a curing device 2033 that may bedisposed in or on a housing 2034. The housing 2034 is disposed over theweb 2012 such that the web 2012 and the patterned surface 2028 on thebacking material 2017 may pass thereunder. The curing device 2033 may bea thermal oven, an ultraviolet (UV) light emitter, or combinationsthereof. In one embodiment, the curing device 2033 may include one orboth of a laser source 2036 and an electron beam emitter 2038 that maybe used to cure the material deposited by the print heads 2027 formingthe patterned surface 2028. In some embodiments, when the electron beamemitter is utilized, the pad manufacturing system 2000A may bepositioned in an enclosure where the pressure can be controlled. Thelaser source 2036 and the electron beam emitter 2038 may be utilizedalone or in combination with the thermal or UV energy. In someembodiments, the laser source 2036 and the electron beam emitter 2038may be used in a spot curing process where specific portions of thepatterned surface 2028 are targeted. The spot targeting by the lasersource 2036 or the electron beam emitter 2038 may heat discrete regionsof the patterned surface 2028 to create a surface of the discreteregions that may be harder or less compressible than the surroundingportions. The laser source 2036 may also be used to ablate portions ofthe patterned surface 2028 to create a fine texture thereon.

FIG. 2000B is a schematic side view of another embodiment of a padmanufacturing system 2000B. The pad manufacturing system 2000B includesthe conveyor 2010 having the feed section 2002, the print section 2004and the curing section 2006 that may be similar to the pad manufacturingsystem 2000A of FIG. 20A. The pad manufacturing system 2000B may alsoinclude a wind-up section 2009 for use in manufacturing a polishingarticle 2029 for use in a roll-to-roll system. The wind-up section 2009includes a take-up roll 2040 where the polishing article 2029 having thepatterned surface 2028 printed thereon may be wound. The take-up roll2040 may be removed from the pad manufacturing system 2000A to beutilized as the supply roll 2018 in the roll-to-roll platen assembly.During manufacturing, the take-up roll 2040 may be coupled to a motioncontrol device 2042. The motion control device 2042 may be a motorand/or include a brake system that controls the winding speed of thetake-up roll 2040. In some embodiments, the pad manufacturing system2000B is utilized to print a plurality of printed pads 2008 (shown inFIG. 20A) that may be used as the pad assembly 1913 in the platenassembly 1911 of FIG. 19.

The pad manufacturing system 2000B includes a supply roll 2016 thatcontrollably unwinds a web 2012 that moves over the conveyor 2010 to thetake-up roll 2040. The web 2012 may be a backing material similar to thebacking material 2017 described in FIG. 20A. Motion of the web 2012 aswell as the conveyor 2010 and the take-up roll 2040 may be controlled bymotion control devices and a controller similar to the pad manufacturingsystem 2000A described in FIG. 20A and the description is omitted inFIG. 20B for the sake of brevity.

The pad manufacturing system 2000B includes an optional pretreatmentsection 2044 positioned between the feed section 2002 and the printsection 2004. The pretreatment section 2044 may be used to form anadhesive or release layer onto the web 2012. Alternatively, an adhesiveor release layer may be formed at the print section 2004 using the 3Dprinting station 2024. When the pretreatment section 2044 is used, aslot/die coater 2046 may be used to deposit a layer or layers onto theweb 2012. Additionally, a curing station 2048, utilizing UV light orheating elements, may be used to cure material deposited by the slot/diecoater 2046.

In this embodiment, the 3D printing station 2024 comprises an array ofprint heads 2026. The print heads 2026 may be used to optionally form anadhesive or release layer on the web 2012 as well as to form thepatterned surface 2028 on the web 2012. In one example, multiple rowsand columns of print heads 2027 may span the width of the conveyor 2010and a portion of the length of the conveyor 2010. In some embodiments,one or more of the print heads 2026 may be movable relative to theconveyor 2010. The print heads 2026 would be coupled to the materialsource 2025 as described in FIG. 20A.

The curing section 2006 may include one or both of an optionalelectromagnetic energy source 2050 and a thermal curing device 2052. Theelectromagnetic energy source 2050 may be one or a combination of alaser source or an electron beam emitter as described in FIG. 20A. Thethermal curing device 2052 may be an oven or a UV light array.

The pad wind-up section 2009 includes the take-up roll 2040 where thepolishing article 2028 may be wound. The take-up roll 2040 may beremoved from the pad manufacturing system 2000A to be utilized as thesupply roll in a roll-to-roll platen assembly.

FIG. 21A is a schematic cross-sectional view of one embodiment of a 3Dprinting station 2024A that may be used in the pad manufacturing system2000A of FIG. 20A or the pad manufacturing system 2000B of FIG. 20B.FIG. 21A shows a portion of one embodiment of a polishing pad 2102manufactured using a 3D printing process. The polishing pad 2102 may bethe pad assembly 1913 described in FIG. 19, the printed pad 2008 (shownin FIG. 20A) or the polishing article 2029 (shown in FIG. 20B). 3Dprinting offers a convenient and highly controllable process forproducing polishing articles with abrasives embedded in specificlocations within the polishing layer. The polishing pad 2102 may beprinted on a support 2100, which may be the backing material 2017 ofFIG. 20A or the web 2012 of FIG. 20B.

Referring to FIG. 21A, at least a polishing layer 2105 of the polishingpad 2102 is manufactured using a 3D printing process. In themanufacturing process, thin layers of material are progressivelydeposited and fused on the support 2100 while the support is moved alongthe arrow indicated by A (in the X direction). For example, droplets2110 of pad precursor material (from the material source 2025 of FIG.20A) can be ejected from a nozzle 2126 of a droplet ejecting printer2115 to form a plurality of layers 2120A, 2120B and 2122. The layers mayform a solidified material 2125 comprising the pad precursor materialenabling sequential deposition of other layers thereon. The dropletejecting printer 2115 may be similar to an inkjet printer, but uses thepad precursor material rather than ink. The nozzle 2126 may betranslated in one or both of the X and the Y direction while the support2100 is continuously or intermittently moved in the X direction duringmanufacturing.

In one example, a first layer 2120A may be deposited by ejection ofdroplets 2110 onto the support 2100. Subsequent layers, such as layers2120B and 2122 (other layers therebetween are not called out for thesake of brevity), can be deposited on the first layer 2120A aftersolidification. After each layer is solidified, a new layer is thendeposited over the previously deposited layer until the full3-dimensional polishing layer 2105 is fabricated. Solidification can beaccomplished by polymerization. For example, the layers of pad precursormaterial can be a monomer, and the monomer can be polymerized in-situ byUV curing or thermally. The pad precursor material can be curedeffectively immediately upon deposition, or an entire layer of padprecursor material can be deposited and then all the deposited layerscan be cured simultaneously.

Each layer may be applied by the nozzle 2126 in a pattern stored in a 3Ddrawing computer program that is provided on a controller 2111. Eachlayer 2120A, 2120B and 2122 may be less than 50% or less than the totalthickness of the polishing layer 2105. In one example, each layer 2120A,2120B and 2122 may be less than 10% of the total thickness of thepolishing layer 2105, for example less than 5%, such as about less than1% of the total thickness of the polishing layer 2105. In oneembodiment, the thickness of each layer may include a thickness of about30 microns to about 60 microns or less, such as on the order ofnanometers (e.g., 1 to 100 nanometers), and even to picoscale dimensions(e.g., (10⁻¹² meters).

The support 2100 can be a rigid base, or a flexible film, such as alayer of polytetrafluoroethylene (PTFE). If the support 2100 is a film,then the support 2100 can optionally form a portion of the polishing pad2102. For example, the support 2100 can be the backing layer 2017 or alayer between the backing layer 2017 and the polishing layer 2105.Alternatively, the polishing layer 2105 can be removed from the support2100 and the layers 2120A and 2120B may form the backing layer 2017.

In some embodiments, abrasive particles may be dispersed in the droplets2110 of pad precursor material. The abrasive particles may be locallydispensed into polishing layer 2105 during formation of each of thelayers. Local dispensing of the abrasive particles may assist inminimization of agglomeration. In some embodiments, abrasive particlescan be premixed with a liquid thermoset polymer precursor. Continuousagitation of the mixture of the thermoset polymer precursor and theabrasive particles prevents agglomeration of the particles, similar toapparatus used to homogenize ink pigments used in ink jet printers. Inaddition, the continuous agitation of the mixture ensures fairly uniformdistribution of the abrasive particles in the precursor material. Thiscan result in a more uniform distribution of particles through thepolishing layer, which can lead to improved polishing uniformity and canalso help avoid agglomeration.

The premixed mixture may be dispensed from a single nozzle (e.g., thenozzle 2126) according to a particular pattern. For example, thepremixed mixture can be uniformly dispensed to produce a homogeneouspolishing layer 2105 having a uniform distribution of embedded abrasiveparticles throughout the thickness of the polishing layer 2105.

FIG. 21B is a schematic cross-sectional view of one embodiment of a 3Dprinting station 2024B that may be used in the pad manufacturing system2000A of FIG. 20A or the pad manufacturing system 2000B of FIG. 20B.FIG. 21B shows a cross-sectional view of a portion of another embodimentof a polishing pad 2132 manufactured using a 3D printing process. Thepolishing pad 2132 may be the pad assembly 1913 described in FIG. 19,the printed pad 2008 (shown in FIG. 20A) or the polishing article 2029(shown in FIG. 20B).

As shown in FIG. 21B, the polishing pad 2132 is formed by the dropletejecting printer 2115 to include a plurality of structures 2150separated by grooves 2155 based on instructions from a CAD program. Thestructures 2150 and grooves 2155 may form the polishing layer 2105. Asublayer 2130 may also be formed with the polishing article by thedroplet ejecting printer 2115. The sublayer 2130 may be the backinglayer 2017 (shown in FIG. 20A). For example, the sublayer 2130 and thepolishing layer 2105 could be fabricated in an uninterrupted operationby the droplet ejecting printer 2115. The sublayer 2130 can be providedwith a different hardness than the polishing layer 2105 by using adifferent precursor and/or a different amount of curing, for example, adifferent intensity or duration of UV radiation. In other embodiments,the sublayer 2130 is fabricated by a conventional process and thensecured to the polishing layer 2105. For example, the polishing layer2105 can be secured to the sublayer 2130 by a thin adhesive layer suchas a pressure sensitive adhesive.

In FIG. 21B, a print head 2126A having a nozzle 2135, can be used todispense a pure liquid thermoset polymer precursor, while a print head2126B having a nozzle 2135 may be used to liquid thermoset polymerprecursor or a molten thermoplastic having abrasive particles 2145contained therein. Droplets 2140 of the abrasive particles 2145 may bedispensed only at selected locations on the polishing pad 2132. Theseselected locations collectively form the target printing pattern of theabrasive particles and can be stored as a CAD-compatible file that isthen read by an electronic controller (e.g., the controller 2111) thatcontrols the droplet ejecting printer 2115. Electronic control signalsare then sent to the droplet ejecting printer 2115 to dispense thepremixed mixture only when the nozzle 2135 is translated to the positionspecified by the CAD-compatible file.

Alternatively, instead of using a liquid thermoset polymer precursor,the abrasive particles 2145 can be premixed with a molten thermoplastic.In this embodiment, the mixture with abrasive particles 2145 is alsocontinuously agitated prior to being dispensed. After the mixture isdispensed from the droplet ejecting printer 2115 according to a targetprinting pattern, the molten portion of the mixture cools andsolidifies, and the abrasive particles 2145 are frozen in place. Thecontinuous agitation of the mixture ensures fairly uniform distributionof the abrasive particles 2145 in the precursor material. This canresult in a more uniform distribution of particles 2145 through thepolishing layer, which can lead to improved polishing uniformity and canalso minimize agglomeration.

Similar to the case when liquid thermoset polymer precursor is used, thethermoplastic mixture can be uniformly dispensed to produce a uniformdistribution of abrasive particles 2145 across the entire polishinglayer 2105. Alternatively, the thermoplastic mixture containing theabrasive particles can be dispensed only at selected locations of thepolishing layer 2105, according to a target printing pattern of theabrasive particles 2145 that is stored as a CAD-compatible file and readby an electronic controller used to drive the droplet ejecting printer2115.

Rather than dispensing abrasive particles in a suspension from thenozzle 2135 coupled to the print head 2126B, abrasive particles can bedispensed directly in powder form from the nozzle 2135 of the print head2126B, while the nozzle 2135 of the print head 2126A is used to dispensethe pad polymer precursor. In one embodiment, the polymer precursor isdispensed before the abrasive particles 2145 are dispensed into thedeposited polymer material, and the mixture is then subsequently cured.

Although 3D printing is particularly useful to construct the polishingpad 2132 using abrasive particles 2145, for example, alumina, ceria, andothers, that would be prone to agglomeration, this approach can be usedto dispense other abrasive particles. Thus, the abrasive particles caninclude silica, ceramic oxides, metals and hard polymers.

The droplet ejecting printer 2115 can deposit particles 2145 that areeither solid or particles 2145 that have a hollow core. The dropletejecting printer 2115 can also dispense different types of particles,some of which can undergo chemical reactions during CMP processing toproduce target changes on layer or layers of the polishing pad 2132 aswell a chemical reactions with a substrate that is being polished.Examples of chemical reactions used in CMP processing include chemicalprocesses that occur within the basic pH range of 10-14 that involve oneor more of potassium hydroxide, ammonium hydroxide and other proprietarychemical processes used by manufactures of slurry. Chemical processesthat occur within an acidic pH range of 2-5 involving organic acids suchas acetic acid, citric acid are also used in CMP processing. Oxidizationreactions involving hydrogen peroxide are also examples of chemicalreactions used in CMP processing. Abrasive particles 2145 can also beused to provide mechanically abrasive functions. The particles 2145 canhave sizes up to 1 millimeter, or less, such as 10 microns, or less, forexample 1 micron, or less. The particles 2145 can have differentmorphology, for example, the particles 2145 can be round, elongated orfaceted.

The 3D printing approach allows tight tolerances to be achieved inpatterns of the polishing layer 2105 and high tolerances in thedistribution of abrasive particles 2145 that are embedded in thepolishing layer 2105 due to the layer-by-layer printing approach.

Polishing Pads

FIG. 22 shows a portion of one embodiment of a polishing pad 2200 thatmay be used as the pad assembly 1913 described in FIG. 19, the printedpad 2008 (shown in FIG. 20A) or the polishing article 2029 (shown inFIG. 20B). The polishing pad 2200 includes a polishing surface 2205forming the patterned surface 2028 of FIGS. 20A and 20B. The polishingsurface 2205 includes a plurality of pores 2232 formed in the polishingmaterial 2270. The polishing material 2270 may be bound to the backingmaterial 2222 by a suitable adhesive 2219 that is chosen for resistanceto chemical and physical elements used in CMP processes. The pores 2232in the polishing pad 2200 are substantially circular or oval shapes, butmay comprise other annular geometric shapes, such as a cone or hollowfrustum, i.e., a cone between substantially parallel planes. Thepolishing pad 2200 may also be formed to match any of the polishing paddesigns illustrated in FIGS. 14A-14O or other designs described herein.

In one embodiment, the pores 2232 may be hollow (i.e., empty space) thatare sized and/or spaced to enhance slurry retention and aid in rollingof the polishing pad 2200. In other embodiments, the pores 2232 may befilled at least partially with a first material 2210 that is differentthat the polishing material 2270 (a second material 2212). The firstmaterial 2210 may be a polymer material that has a different reactivityto a curing method as compared to the second material 2212. For example,in one embodiment, the second material 2212 may be curable with UVenergy while the first material 2210 is not significantly affected by UVenergy. However, the first material 2210 may be cured thermally in oneembodiment. In other embodiments, the first material 2210 and the secondmaterial 2212 may be cured at a different rate. In one embodiment, thepolishing pad 2200 may be differentially cured using the first material2210 and the second material 2212. In one example of differentialcuring, the first material 2210 and the second material 2212 of thepolishing pad 2200 may be cured with UV energy that does not cure thefirst material 2210. This may make the second material 2212 harder thanthe first material 2210 which may add compressibility and/or flexibilityto the polishing pad 2200 as the first material 2210 is more viscousthan the second material 2212.

In one embodiment, the first material 2210 is thermally cured to makethe pores 2232 having the first material 2210 disposed therein harder,but still softer and more compressible than the second material 2212. Inanother embodiment, the first material 2210 in the pores 2232 is curedthermally by heat produced by friction during a substrate polishingprocess. In this embodiment, the first material 2210 may be cured to beharder than the second material 2212 thus forming domains on thepolishing surface 2205 that are harder than the surrounding secondmaterial 2212.

In other embodiments, the first material 2210 may have a differentreactivity with electromagnetic energy, such as a beam or beams ofenergy from the electromagnetic energy source 1958 (shown in FIG. 19)when compared with the second material 2212. The different reactivitymay be used to form a micro texture on the polishing surface 2205. Thedifferent reactivity between the first material 2210 and the secondmaterial 2212 may provide that the first material 2210 will be ablatedat a greater rate than the second material 2212, or vice versa. Thepores 2232 may be micron sized or nano sized materials that form micronsized or nano sized domains within the polishing surface 2205 of thepolishing pad 2200. In one embodiment, the pores 2232 may include a meandiameter which is less than about 150 microns to about 10 microns, orless.

One embodiment of the present disclosure provides a polishing padincluding a composite pad body. The composite pad body includes one ormore first features formed from a first polymer material, and one ormore second features formed from a second polymer material. The one ormore first features and the one or more second features are formed bydepositing a plurality of layers comprising the first polymer materialand second polymer material. One of the first features or secondfeatures are differentially cured to provide a differential hardness orother useful material property therebetween. In one embodiment, the oneor more first features and the one or more second features are arrangedalternatively across the pad body. In one embodiment, the one or morefirst features are thicker than the one or more second features so thatgrooves and/or channels are formed on a top surface of the composite padbody. In one embodiment, the one or more first features comprise aplurality of concentric rings separated by the one or more secondfeatures. In one embodiment, the one or more first features comprise aplurality of columns surrounded by the one or more second features. Inone embodiment, the one or more first features and one or more secondfeatures are formed by 3D printing. In one embodiment, the polishing padfurther includes two or more composite pad bodies joined together atedges thereof. In one embodiment, the polishing pad further includes asub pad body, wherein the composite pad body is formed over the sub padbody. In one embodiment, the one or more first features comprise a porehaving a third material disposed therein. The third material is athermally cured material. In one embodiment, the first polymer materialhas a first Young's modulus and the second polymer material has a secondYoung's modulus. In one embodiment, the first material has a highermodulus of elasticity than the second material.

Although polishing pads described herein are circular in shape,polishing particles according to the present disclosure may include anysuitable shape, such as polishing webs configured to move linearlyduring polishing.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

The invention claimed is:
 1. A polishing pad, comprising: a compositepolishing pad body comprising: one or more first features formed from afirst material, wherein the first material comprises a first materialcomposition formed by depositing droplets of a second material and athird material within a plurality of layers that form at least a portionof each of the one or more first features; and a base material layerformed from a fourth material, wherein the fourth material comprises asecond material composition formed by depositing droplets of a fifthmaterial and a sixth material within a plurality of layers that form atleast a portion of the base material layer, wherein the one or morefirst features extend from the base material layer, and a surface ofeach of the one or more first features form a polishing surface of thecomposite polishing pad body.
 2. The polishing pad of claim 1, whereinthe first material has a first hardness and the fourth material has asecond hardness different from the first hardness.
 3. The polishing padof claim 2, wherein the first hardness is greater than the secondhardness.
 4. The polishing pad of claim 1, wherein the one or more firstfeatures and the base material layer are arranged to achieve apredetermined Young's modulus or a predetermined storage modulus andloss modulus across the composite polishing pad body.
 5. The polishingpad of claim 1, wherein the first material has a higher Young's modulusthan the fourth material.
 6. The polishing pad of claim 1, wherein theone or more first features comprise a plurality of concentric ringsseparated by the base material layer.
 7. The polishing pad of claim 1,wherein the one or more first features comprise a plurality of postssurrounded by the base material layer.
 8. The polishing pad of claim 1,wherein the one or more first features and base material layer areformed by printing the each of the plurality of formed layers.
 9. Thepolishing pad of claim 1, further comprising one or more observationwindows, wherein the one or more observation windows are formed throughand/or abut the one or more first features or the base material layer.10. The polishing pad of claim 1, wherein the first material and thefourth material each comprises a polymer material.
 11. The polishing padof claim 10, wherein the polymer material comprises an acrylate.
 12. Thepolishing pad of claim 1, wherein the first material comprises anacrylate.
 13. A polishing pad, comprising: a composite polishing padbody comprising: one or more first features formed from a firstmaterial, wherein a surface of the one or more first features form apolishing surface, the first material has a first hardness, and thefirst material comprises a first polymer material and a second polymermaterial; and a base material layer formed from a second material,wherein the second material has a second hardness that is less than thefirst hardness, and the second material comprises the first polymermaterial and a third polymer material, wherein the one or more firstfeatures extend from the base material layer, and wherein aconcentration of the first polymer material in the first material isgreater than the concentration of the first polymer material in thesecond material.
 14. The polishing pad of claim 13, wherein the one ormore first features and the base material layer are formed by depositinga plurality of layers comprising the first material and the secondmaterial.
 15. The polishing pad of claim 13, wherein the one or morefirst features and the base material layer are arranged to achieve apredetermined Young's modulus or a predetermined storage modulus andloss modulus across the composite polishing pad body.
 16. The polishingpad of claim 13, wherein the one or more first features and basematerial layer are formed by printing.
 17. The polishing pad of claim13, further comprising one or more observation windows, wherein the oneor more observation windows are formed through and/or abut the one ormore first features or the base material layer.
 18. The polishing pad ofclaim 13, wherein the first polymer material comprises an acrylate. 19.The polishing pad of claim 13, wherein the first material is formed bydepositing droplets of the first polymer material and the second polymermaterial.
 20. The polishing pad of claim 13, wherein the second materialis formed by depositing droplets of the first polymer material and thethird polymer material.